Venturi orchard heater



may 27 1924 1,495fi48 w. c. SCHEU VENTURI ORCHARD HEATER Filed July 5,,1922 Fatented May 27, 1924.

UhliTEE STATES WILLIAM C. SCHEU, F LOS ANGELES, CALIFORNIA.

VENTURI ORCHARD HEATER.

Application filed July 5, 1922. Serial No. 572,783.

To all whom it may concern Be it known that VVILLIAM C. SCHEU, citizenof theUnited States, residing at Los 4 Angeles, in the county of LosAngeles and 5 State of California, has invented certain new and UsefulImprovements in Venturi Orchard Heaters, of which the following is aspecification.

This invention relates to an improved de- X0 vice for protectingorchards from damage by frosts. It is particularly adapted to burnliquid fuels of various grades and qualities from the heavy crude oilsand distillates to the finer and lighter grades.

\Vhen damaging frosts and freezes occur during the blossom and fruitperiod and 1t becomes necessary to resort to artificial heat to protectthe trees from frost damage it is of the utmost importance that theheating devices be of such a construction that the consumption of fuelis so regulated and controlled through the medium of automatic andmanually controllable means that practically no smoke is produced.

Such a condition produces the maximum heat with the least consumption offuel, and where all of the gas generated from the fuel is consumed thereis a minimum of carbonaceous and asphaltic material or residue depositedaround the interior of the heaters to interfere with their perfectoperation.

The present invention embodies a construction and controllability thatwill produee practically smokeless heat, from any burnable grade ofliquid fuel, for prolonged periods, with the minimum of care and at-'iention and will hold and maintain combustion as long as any fuelremains in the heater.

()ne object of the present invention is to incorporate in the design andconstruction of an orchard heater an easy and reliable means forigniting the fuel in a battery of distributed heaters.

Another object of the invention is to provide. a combustion stack ofunique design and construction, whereby a practically perfect. smokelesscombustion is obtained with a short er stack than has heretofore beenpossible.

Another object of the invention is to provide a combustion stack in twoeasily separable sections, so designed and proportioned that the topsection will slip loosely over the lower section and form a rain shieldtherefor when the heater is out of use. This top section, so used, incombination with a small cap to close the stack opening giving completeprotection against the ingress of rain.

Another objectiof the invention is to provide a combustion stack made oftwo tapering sections. The lower section resting on the theater with itslarge opening down and the reduced opening up. The second sect-ionresting on the first section with its smaller opening engaging thesmaller opening of the lower section, with its larger opening upward.This arrangement produces a combustion stack of Venturi construction.

Another object of the invention is to provide air inlet openings in thelower section of the combustion stack of such a shape and arrangement aswill greatly facilitate the combustion of gases within said stack.

Another object of the invention is to provide a device located in oradjacent the air inlet opening of the cover to act automati cally as adeflector or retardent member, whereby the gas generating flame at ornear said air inlet opening is prevented from being wholly drawn awayfrom said opening, or from the surface of the oil, by the strong draftpassing through the combustion stack, and thereby a fire is maintainedat or adjacent said air inlet opening at'all times and during allconditions of operation wheither using a light or a heavy grade of fueOther objects and advantages will become apparent as the constructionand operation are made more manifest by a study of the drawingsaccompanying this specification and claims.

It will be observed that like figures of reference apply to like partsof the drawupper stack section is reversed and is resting over theoutside of the lower stack section and completely enveloping the same toact as a rain shield. Just above the stack in this view is shown a smallcap for closing the stack opening to prevent rain reaching the interiorof the heater through said openmg.

(All

Figure 3 is a plan of Figure 1.

Figure 4.- is a plan of the deflector (lGY-lQG- as shown in connectionwith the ignition cup in Figure 1.

This invention comprises a an orchard heater having a fuel receptacle orbowl 1', a cover 2 therefor. Arranged onthe cover 2 is an air inletopenin 5 having an upturned flange 6 around its edge to prevent waterrunning into the opening.

Arranged directly under the air opening 5 is an ignition cup 7 securedto the under side of the cover 2. This cup 7 has an annu lar recess 8extending around a central opening 9, the purpose of Whichis to form apocket or cup for retaining a portion of ignition fuel for starting atire and the generating of gaswithin the heater.

The edge of the annular recess 8 also acts as a support for a member 10of disc form and having a depending flame deflector 11 attached theretoand extending down into the fuel receptacle to near the bottom thereof.

Arranged over the air inlet opening 5 is a perforated plate 12 pivotedto the cover 2 and ada ted to swing over the opening 5. Pivotedcentrally on the plate 12 is a shutter 13 having an elongated opening14, the shutter 13 is adapted to be turned on the plate 12 and exposedthe openings therein as may be necessary to admit the air required tomaintain combustion in the gas generating space in the heater.

The sectional Venturi combustion stack comprising a part of thisinvention is made as follows:

The lower section 3 is detachably secured to the cover 2 by means of afriction joint.

The wall of this stack section is provided with openings 16, made byslitting and bending the metal of the wall inward forming invertedlouvers, which have the effect of directing the incoming air upwardalong Bid till

the inside of the stack, and seem to more or less prevent the incomingair from going toward the center of the stack. This effect has produceda much better combustion of the gases, probably through a better mixingof the air and gases without materially interfering with their upwardmovement.

' The side walls of this lower section 3 are made tapering so that theupper end is somewhat smaller in area than the lower end that rests. onthe cover. A short distance down from the upper or small end anoutturned head is formed in the wall of the stack.

The upper section 4 of this combustion stack is also made tapering sothat one end has a larger opening than the other. a The small end ofthis upper section is just large enough to slip freely over the smallend of the lower section 3 and abut against the outturned head 3 onsection 3.

An inturned head 4: near the small end of the section 4: encircles theend of the section incense 3 and thereby gives stability to theassembled sections.

Thisassembled" stack possesses the following features of construction.

The lower end resting on the cover 2 is of large area, the center Wherethe two sections join together form a restricted area, while the topforms a large area.

This combination produces a Venturi stack.

The combination of elements as here assembled, makes possible for thefirst time, to my knowledge, the combustion of gases and air withpractically smokeless results and a combined stack length very muchlessthan has been possible heretofore, resulting in a much cheaperstructure, lighter in weight and much less affected by winds tending toblow the stacks 0d the heaters.

Tn combustion stacks having friction joints it has been found that wherethe double thickness of the joint occurs excess heating takes placewhich quickly disintegrates the metal at this point and causes rapidburnin 0d of these joined ends, which then have to be trimmed oil, thusshortening the total length of the stack. After being trimmed a fewtimes the stack is so shortened as to very materially aflect its burningefficiency.

It will he noted that while it join these sections with a slip joint,the interposition of beads 3 and 4: give me a rigid enough connectionfor all practical purposes and in addition provide a much needed andvery desirable air space between the metal surfaces of the joint asdesignated 3*. A

This air space will greatly mitigate the destructive action of'theintense heat at this point and thus add greatly to the life of thestacks.

The arrangement of the inward, upwardly inclined louveropenings; thelarge area openings at the entrance and exit of the stack; the graduallytapered walls converging toward the junction of the stack sections allcombine'to produce a combustion chamber of very marked eficiency, with ashorter total leplgth of stack than has been heretofore pos- S1 e..

All previous short stack heaters, with straight stacks, or with onesection tapering, have been consistent smoke producers and have never tomy knowledge been eficient heating devices.

Owing to the fact that various grades and qualities of liquid fuel mustbe consumed at times, it is very desirable that means be providedwhereby a tire will be maintained in the heaters regardless of thequality Ofilillt; fuel being used, the only manual adjustment necessary,being the regulation from time to time of the air supply through themedium of the air control members 12 and 13.

The feature of this invention that acts Mill lltl' a menses tion to themovement of the flame adjacent the air inlet opening to prevent .it frombeing drawn away from this location by the draft from the stack.

When this type of heater is properly adjusted to suit the quality andgrade of fuel being used, a roaring fire is maintained just at the airopening and reaching down and around the obstructive plate 11, to andacross the surface of the fuel toward the opening into the stack.

The oilice of this intense fire, at and near the air opening in thecover, is to generate a gas from the surface of the oil, which gas asgenerated is being constantly drawn into the stack for combustion, andwhen the generating fire is properly maintained the necessary amount ofgas is continually generated to maintain proper combustion in the stackand the heater is consequently producing the maximum heat with practically no smoke.

The whole situation is entirely dependent on being able to maintain aproper and suflicient generating flame adjacent the air inlet opening inthe cover.

The obstructive member 11 at this point should be only sufficientlyeffective to prevent the generating fire from being pulled away from thes ace adjacent the air inlet opening, otherwise the excess retardingeffect of too much obstruction might seriously interfere with getting amaximum efliciency out of the heaters.

To start these heaters in operation it is only necessary that the plate12 over'the air inlet opening, be swung to one side and a small quantityof burning oil, such as a mixture of gasolene and kerosene, be pouredinto the cup 8, it being understood that the stack has first beenadjusted to extendedposition.

This burning ignition oil is applied from a can having a long spout withan asbestos wick in the end, such as is well known by those skilled inthe art.

This burning oil will bubble over the edge of the flange of the ignitioncup, and some will run down on the plate 11. 'Sometimes a small bunchofexcelsior is placed in the air opening and burning oil poured on it,which will immediately ignite. it. The draft from the stack pulls theflame from the air inlet opening down into the heater over the surfaceof the oil and in a few seconds gas begins to form and pass into thestack where the air coming in through the louver openings 16 mixes with1t and there is formed a combustive mixture .which burns quitevigorously and smokelessly and produces an intense heat.

Part of the generated gas of course goes to maintain the generatingflame adjacent the air inlet opening. As'soon as suflicient gas isgenerated to maintain the generating flame in the receptacle and theheating flame 1n the stack, the plate 1:2 is moved around over the airinlet opening and the shutter 13 is adjusted relative to the air holesin the plate 12 to give the proper quantity of air necessary to maintainthe intensity of fire desired.

At the beginning of operation with the heater nearly full of oil, lessair is required, but as the fuel is consumed, and the surface of the oilrecedes down away from the air inlet opening, the generating flameincreases in size and needs more air. Then is when it becomes necessaryto readjust the shutter 13 to give the additional air required. Thisadjustment is'necessary several times during the period that one fillingof the bowl is being consumed.

It is the practice where a number of heaters are in operation during acold night to apportion a given number of heaters to each of severalattendants who pass from one to the other and adjust the air supply asmay be required to suit existing conditions.

With the problem solved of always maintaining a fire under Varyingconditions, which is the result of my deflector, the operation of alarge battery of heaters becomes a very simple matter and can beattended to by unskilled attendants.

It is thought that my description herewith will enable anyone skilled inthe art to opera'te these heaters successfully, and while I havedescribed and illustrated the invention in its preferred embodimentI donot wish to be understood as confining or limiting the invention to theexact details of construction and arrangement as shown, but wish to beunderstood as claiming the invention as broadly as the state of the artwill permit.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

- 1. An orchard heater comprising a fuel ceptacle, a cover therefor,controllable air inlet means on saidQcover, a combustion stackcomprising two separable tapered units mounted on and extending upward.from said cover, air inlet means in the walls of one of said taperedstack units, the smaller ends of said tapered stack units beingseparably connected whereby a tapered. opening is formed through saidstack with the opening from the said fuel receptacle into said stackbeing free and unobstructed.

3. An orchard heater comprising a fuel receptacle, a cover mounted onsaid receptacle and having controllable air inlet openings thereon, anunobstructed opening in said cover, a combustion stack comprisingseparable tapered units mounted over said opening in said cover andextending upward therefrom, air inlet means in the side walls of onetapered unit of said stack, said tapered stack units being connected endto end with a separable slip joint whereby an unobstructed Venturipassageway is established from said fuel receptacle through said stack.

4. An orchard heaterhaving a fuel receptacle and a cover thereon, astack mounted on said cover comprisin separable connected units, theunit resting directly on said cover having converging side walls and theunit resting on said converging unit having diverging side walls wherebyan unobstructed venturi shaped passageway from said receptacle is formedthrough said superposed stack units.

5. An orchard heater having a fuel receptacle and a cover thereon havingcontrollable air inlet means and an ignition device located adjacentsaid air inlet means, a stack mounted on said cover comprising separableconnected units, the unit resting directly on said cover havingconverging side walls and the unit resting on said converging unithaving diverging side walls whereby an unobstructed venturi shapedpassageway trom' said fuel receptacle is formed through said superposedstack units.

6. An orchard heater comprising a fuel receptacle and a cover thereonhaving an unobstructed gas-passage and a controllable air inlet opening,an ignition cup located under said air inlet opening and a flamedefiector member mounted under said ignition cup and extending down intosaid fuel receptacle, a two part combustion stack mounted on said coverand connected with said gas passage, said stack having air inletopenings in its side walls, said stack parts comprising two separabletapered units superposed one over the other with their small ends connected by means of a loose slip joint whereby a venturi shapedunobstructed passageway is formed therethrough.

7. A combustion stack for use with oil burning orchard heaters,comprising two tapered units separably connected by their small ends toform a Venturi tube, the slip joint connecting said ends having enlargedside.

tees-pas portions whereby said oint is provided with an air spaceseparating the walls of the slip joint to prevent overheating thereof,

8. A. stack for use with oil burning orchard heaters comprising twotapering units separably connected at their small ends by a loose slipjoint to form a Venturi tube, the said slip joint connecting said unitshaving an air space to prevent overheating .ot the double thickness ofmetal at said joints, one of said units having air inlet openings initsside walls termed by making circumferential slits and bending the metalunder said slits inward to form small wall portions for deflectingentering airupward through the said venturi passageway.

9. A venturi shaped combustion stack for use with oil burning orchardheaters comprising two tapered members, beads formed adjacent the smallends of each of said members, whereby when said members are separablyconnected to form a venturi tube shaped stack the joint termed byuniting the small ends of said tapered members is provided with an airspace to prevent over heating and burning of the metal of the stack endsforming said'joint.

10; A. combustion stack for orchard heaters comprising a membermade upof two axially tapering sections, said sections being joined by theirsmall ends with a loose separable slip joint to form a completecombustion chamber, beads formed in the metal at said loose slip jointto separate the metal portions -forming said joint and provide aninsulating airspace to prevent overheating and burning of said stacksections, with air inlet means in one of said stack sections to maintaincombustion within said stack.

H. A combustion stack for oil burning orchard heaters comprising amember made up of axially tapering sections mounted one above the otherto form a venturi shaped passageway therethrough, one of said sectionshaving air inlet means in its side walls, the other said section beingadapted when reversed to slip loosely over the section having the airopenings and act as a protective shield therefor and a cap to close theupper opening of said reversed stack section,

12. An orchard heater comprising a fuel receptacle, a cover therefor, atwo part tapered stack extending upward from. said cover and having aventuri shaped opening therethrough, one of the said tapering sectionsof said stack adapted to be removed from the other said section,reversed and nested over the other said section to term protectiveshield therefor and a cap for closing the opening of said nested stacksections.

in testimony whereof l herewith aiiix my signature,

VfltLlL-IAM Stdlllldll,

o r c a to

